Method of preserving dibasic calcium hypochlorite



Patented Jan. 14, 193

HEBMANN S. SCHULTZE, 0F GRIESHEIM-ON-THE-MAIN, GERMANY, ASSIGNOB TO I. G.

FABBENINDUSTRIE AKTIENGESELLSCHAFT, 0F FRANKFORT ON-THE-MAIN, GER- METHOD 01F PRESERVING DIBASIC CALCIUM HYPOCHLORITE No Drawing. Application filed July 25, 1927, Serial No. 208,410, and in Germany August 18, 1926.

This invention relates to a method of preserving the dibasic calcium hypochlorite 2Ca(OH) .Ca(OCl 2 described in "my former specifications atent Nos. 934,467 and 5 1,583,421. According to the method therein described the dibasic hypochlorite is obtained in the form of flat hexagonal crystals the size of which permits an easy separation of the salt from the mother liquor by centrifuging. In this way a product is obtained containing about 40% of active chlorine and 5'10% of moisture.

' It was hitherto considered necessary to free the product from moisture as completely as possible, preferably by heating. The chemists were guided in this respect by former experiences with high grade hypochlorites (see German Patent No. 418494) and bleaching powder (see British Patent No. 242,805)

i 2 in order to desiccate these materials as completely as possible, it has already been proposed to add calcium oxid, or to treat the material with calcium oxid after preliminary dehydration, for instance with hot air.

Now l have found that the dibasic calcium hypochlorite is stable even if containing a water content up to about 15%. By this fact the manufacture of the dibasic calcium hypochlorite is considerably simplified and acis dustless and odorless and that, in desirable contradistinction to bleaching powder, it does not at all attack the wooden transport casks so that-they can be used repeatedly.

I claim 1. The method of handling dibasic calcium hypochlorite which comprises packing the salt into casks in the state in which it is obtained by centrifugating the wet salt.

2. The method of handling dibasic calcium hypochlorite which comprises packing the salt, containing from 5 to about 15% of moisture, into casks.

In testimony whereof I have hereunto set my hand.

HERMANN S. SCHULTZE.

celerated in so far as it is no more necessary to subject the centritugated salt to a special drying process and not even to a washing process. The dibasic calcium hypochlorite is rather practically stable in the state in which it is obtained after the centrifuging process. Even at elevated temperatures the durability is superior to that of common bleaching powder to a surprising extent and practically equals that of the dried dibasic salt, so that the moist product coming from the centrifuge is as tropic-proof as t e perfectly dried salt. Whereas bleaching owder at C. loses about 1%of active 0 orine per day and is therefore nearly com letely decomposed in a little over a month, t e percentage of active chlorine in the moist dibasic by ochlorite as delivered by the centrifu e oni y decreases from 40 to 36-37% under tie same conditions. I

Moist as delivered from the centrifuge 

